Thermostatic device



April 13, 1948. R. w. DE LANCEY 2,439,455

THERMOSTATIC DEVICES Filed June 22, 1945 INVENTOR RALF/f WD5/.AMEV

ATTORNEY Patented Apr. 13, 1948 THERMOSTATIC DEVICE Ralph W. De Lancey, Meriden, Conn., assignor to The Miller Company, Meriden, Conn., a corporation of Connecticut Application June 22, 1945, Serial No. 601,014

The present invention relates to thermostatic devices, and is more particularly directed toward thermostatic devices of the type employing spiral bimetal thermostats for actuating the contacts of a control circuit.

The present invention is suitable for use in connection with airstats and aquastats used in the control oi.7 oil burners and stokers and having manual means for presetting the device to control the circuit at selected temperatures of the medium surrounding the thermal element.

The present invention contemplates a convenient worm and worm wheel arrangement for adjusting the thermostat and the provision with such worm and worm wheel arrangement of a simple indicator' whereby the adjustment may be ascertained.

The accompanying drawings show, for purposes of illustrating the present invention, an embodiment in which the invention may take form, it being understood that the drawings are illustrative of the invention rather thanlimiting the same.

In these drawings:

Figure 1 is a perspective view of the complete device;

Figure 2 is an elevational view showing the circuit open and the parts in position for low temperature control;

Figure 3 is a view similar to Figure 2 showing the parts in position for high temperature control;

Figure 4 is a sectional view on the line ii-il of Figure 2;

Figure 5 is a sectional view on the line 5-5 of Figure 2; and

Figure 6 is a sectional View on the line t-i of Figure 5.

A sheet metal plate I forms the frame element for the entire device. A coupling or bushing il secured to the plate is provided for securing the entire device to a boiler or other structure where temperature conditions are to be employed for controlling a circuit.

The bushing il is counterbored to receive an arbor I2. This arbor is secured to the upper end of .a spiral bimetallic thermostat as indicated at I3. The lower end of the thermostat is secured to a rod or shaft I4 which extends up through the arbor i2. This rod carries an arm i on which is mounted an insulated contact it. The plate IU carries a terminal block il provided with a contact i8 opposite the contact IB.

A subframe I9 is apertured at 20 to iit about the arbor I2 and is held in place by a screw 2i 1 Claim. (Cl. 20G-139) which also forms a stop for the arm I5. The arbor I2 fixedly carries a worm wheel 22. The subfrarne I9 carries a worm 23 in mesh with the worm wheel 22. The worm 23 is anchored in place by a spring 23' which presses it to the left. An operating knob 24 is carried outside a front flange 25 formed on the plate It. Turning the irnob 24 makes it possible to adjust the tension of the bimetal thermostat and determine the temperature at which suiicient expansion in the bimetallic element will occur to cause the contacts lil and I 8 to meet. While the drawing shows a thermostatl of the normally open circuit type, it will be understood that the invention is equally well adapted for use with normally-closed-circuit devices.

The worm 23 carries a nut 2t which is adapted to travel along the worm. When the device is first assembled this nut is loosely received in an opening 2li in an indicator The lower end of the indicator rides along the subirame i9 and may extend down into a slot E@ as shown.

When the factory adjustment of the device is made, the Contact arm is given a predetermined loading, and the parts are broug t to the proper position to have the circuit closed (or opened) at the desired temperature. The nut 25 can then be moved freely along the shaft to the position desired for the indicator 28 and the indicator soldered to it. Thereafter the indicator iii will prevent turning of the nut and will move back and forth as the adjustment is made. `The device is provided with a cover il@ having a slot 3l through which the indicator may be observed.

Since it is obvious 'that the invention may be embodied in other forms and constructions within the scope oi the claim, l wish it to be understood that the particular form shown is but one of these forms, and various modifications and changes being possible, I do not otherwise limit myself in any way with respect thereto.

What is claimed is:

A temperature responsive circuit controller comprising a supporting plate, a mounting bushing secured rearwardly of the plate, an arbor mounted in the bushing, a thermal motor carried by the arbor and including a shaft extending through the arbor and movable about its axis, a contact arm carried'by the shaft, a fixed contact cooperable with the arm, a worm wheel carried by the arbor, the supporting plate having a forwardly extending bracket, apertured to one side of the shaft axis, a subframe secured to the plate and having a front opening in line with RALPH W. DE LANCEY.

4 REFERENCES crrnn The following references are of record in the le of this patent:

Number UNITED STATES PATENTS Name Date De Khotinsky Apr. 26, 1921 Klopsteg et al. May 24, 1927 Klopsteg Oct. 24, 1933 Rlckmeyer June 3, 1941 

